Connecting plug



July 20, 1948. w. o. DE-rwl-:ILER

CONNECTING PLUG Filed Dec. '7, 1946 ZU. C9. Dewevycr ATT/f Patented July 20, 1948 UNITED STAT-Es 'PATENT OFFICE Wilbur 0.*Detweiler, Toronto, ntario,.Cana.da

Applicaticnfecember 7, 194:6,` Serial No. 714.8515

This invention Vrelates-to connecting -plugsrfor electrical appliances. The object of the invention is to devise a plug which may be readily removed from the terminal to which it is connected. A further object of theinvention is to devise a plug which can be removed without touching the appliance to which it is connected.

Plugs of this kind have been devised in the past, but they have all been open to objection on one ground or the other. In general -they have been expensive to manufacture and awkward to use. According to the present invention, a connecting plug has been devised which can be made with but little departurev from the most commonly used construction for such plugs and at very little eXtra expense. It can be removed without touching the appliance to which it is connected, which is an important feature when the plug is used for toasters, heaters, or other appliances which become hot when in use, avoiding burning of the fingers. Inits preferredform the plug is made of two pieces each of which by the use-of removable-mould llers or Stoppers can be made in the some mould. l

The objects of the inventionare attained by the various features of construction hereafter described of which two important features are the provision of a slot or slots in a plunger, which is used for removing the plug from its terminal, combined with means on the plug itself which project into the slot or slots to limit the movement of the plunger and prevent it from being withdrawn from the plug. A further feature of the invention is provision of the inlet for the wiring at one side of the plug in the plane of the contacts so that when in use this connection does not interfere with the operation of the plug removing means. Other features lie in the formation of the guideway from two parts of a two-piece plug and the utilization of the connecting means for the two parts of the plug as the projection which passes through the slot or slots of the plunger. Other features of the invention will hereinafter appear from the following detailed description of the device, which is illustrated, by way of example in the accompanying drawings in which:

Figure 1 is an end view of the connecting plug;

Figure 2 is a side elevation;

Figure 3 is a side View of one of the pieces, showing the plug in its relation to a two-pronged terminal from which it has just been removed and showing in dotted lines the position of the plunger when the plug is in engagement with the terminal;

Figure 4 is an end view;

Figure 5 is a perspective view o f the plunger; and

AFigure 6 is a cross section on the line 6-6 in Figure 2.

In the various Afigures the corresponding parts Vare referred to by corresponding numerals.

VThe plug is formed of two pieces I0 and Il of electrical insulating material, which are substantially identical. Each piece is provided with arlongitudinal rectangular -groove Illa and II*ab respectively which co-operate to form a guideway extending fromcone end to the other of the plug substantially centrally thereof and opening at each end. YThe guideway is wholly enclosed, Withtl'le exceptionof a portion of the upper en d as hereinafter described. s

On either side of the central groove each piece IB and II is provided with a groove IOP and I-Ib, respectively, which co-operate when the parts are secured together to provide recesses for conventional contact lmembers I2 and t3, whichcomprise two slightly concave-convex conductive parts held together at Vone end by screws or bolts in the usual manner.

The upper ends of thegrooves vIl!" and IIb provide space for connecting wires I4 and I5 and these grooves extend across the plug at the upper end forming passageways which intersect the grooves I lla and IIa and provide passageways communicating between the recesses on either side of the guideway to carry one of the wires from one recess to the other for connection with one of the contacts.

A plunger IS is slidable in the guideway formed by the grooves II!a and I I3L and is provided with a head or knob |62. It extends longitudinally through the plug and beyond the ends thereof so that by grasping the plug and pressing on the head or knob I la the plunger may be forced inwardly into engagement with a terminal I1 to Withdraw the plug from terminal prongs IIa and I'Ib which are adapted to enter and contact with the contacts I2 and I3. In practice two lingers will be placed around the enlarged outer or upper end of the plug and the thumb pressed on the knob I 6a to effect the removal of the plug from the terminal prongs.

Longitudinal slots Itb and I6c are provided in plunger I 6 and connecting bolts I8 and I9 provided with suitable nuts on their ends and located substantially on the longitudinal centre line of the plug extend through the two parts Y of the plug and through the slots I 6b and I6cr to serve the double purpose of holding the two pieces of the plug together and at the same time acting as stops to limit the movement of the plunger so that it can be withdrawn only to the point where its lower or inner end is substantially iiush with the lower or inner end of the plug.

Grooves Il]c and II= are formed in each side of each piece of the plug adjacent the upper or outer end thereof at one side, which co-operate to provide between them an aperture to admit the electrical wires I4 and I 5. It will be observed that the line of connection between the two pieces of the plug is substantially in the transverse plane of the contact members I2 and I3 and that the aperture for admission of the wires I4 and I5 is on the same plane. A suitable coiled wire sleeve 2| of ordinary construction may be provided in the usual manner for protecting the wires at their point of entry into the plug and to retain them in an outwardly extending position so that they will not interfere with the operation f plungerY I6.

A suitable piece of nbre board or other insulating material 20 is mounted on shoulders in the plug between the plunger I6 and the passageway which intersects the guideway through which the wire I4 passes for connection with contact I2. In practice each piece of the plug4 will be of identical construction although oppositely disposed so that there is a passageway both above and below the plunger I6 for passage of a wire, but only one such passageway is required since only one of the two wires will pass through the same. By the use of suitable Stoppers, filters, or plugs for closing grooves or recesses not required each piece may be made in the same mould. For instance the mould may be made with a groove on each side for forming the aperture to admit the electric wires. For one piece of the plug this groove can be iilled by a stopper on the left side and for the mating piece it can be closed on the right side.

It is thought that the construction and use of the invention will be apparentrfrom the above description of the various parts and their purpose. It is to be understood that the form of my invention herewith shown and described, is to be taken 410 Number as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of my invention, or the scope of the subjoined claim.

What I claim as my invention is:

A two-piece plug of electrical insulating material, each piece of the plug being formed with a longitudinal substantially central groove extending from one end to the other, said grooves forming between them a longitudinal guideway, a plunger slidably mounted in the guideway and adapted to extend beyond the ends of the plug, whereby by grasping the plug and pressing the plunger the plug may be removed from the terminal to which it is attached, each piece of the plug having formed therein a recess on either side of the central groove, said recesses forming between them spaces, electrical contacts mounted in said spaces, and each piece having grooves extending from the recesses to the eX- terior of the plug adjacent one end thereof and to one side of the plug in the transverse plane of the contacts to provide between them an aperture to admit electrical wires, the plunger having at least one longitudinal slot through it, and the plug being provided with at least one connecting member vextending through both pieces of the plug substantially on the longitudinal centre line thereof and through the slot to connect the pieces and to limit the movement of the plunger relative to the plug.

WILBUR O. DETWETLER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Name Date ONeil Aug. 10, 1909 Kent Dec. 30, 1913 Gaynor Mar. 31, 1925 Thornton, Jr Oct. 13, 1925 Park Jan. 3, 1939 Corrigan Oct. 2l, 1941 

